It is known how in mobile cranes, particularly telescoping cranes, to attach an additional device to the head of the main jib of the base crane. Such a device is used to achieve a jib length that extends even further beyond the maximum jib length of the telescoping crane. The devices are generally designed as modular systems and can be combined as a function of required length or lifting capacity.
Ideally, the individual main elements of the device have a lattice/pipe design in transportable dimensions. The device elements are joined with pins at corresponding points to form a single unit.
In most cases, the additional device will not be carried together with the base crane and must be transported separately. Devices provided specially for this purpose, however, may also be carried together with the base crane, weight and space conditions permitting. The attachment to the main boom head can occur piece by piece, or as a preassembled unit in a known manner with an additional auxiliary crane.
The use of an auxiliary crane entails additional costs because it requires additional personnel to move it close to the setup location. In addition, it is difficult to guide the freely floating and raised additional device with pinpoint precision to the fastening points provided at the jib head of the mobile crane, while keeping the risk of injury for the installers in mind. This means a relatively high expenditure of time for installation.
It is therefore an object of the invention to simplify the attachment of the additional device and make it safer, in particular, to carry it out without the use of an additional auxiliary crane.